Seeking advice/help on camera selection

[mental4astro]

Hi all,

My request is not particularly geared towards AP, which is why I've placed this thread in this forum. AP is not out of the question, but not the primary concern for my question.

Ok, my niche in astro is sketching. My work I chose to photograph as using a scanner is not a good way of faithfully recording artworks, namely because of the lighting situation and resolution.

I've been using a Canon SX60HS for this, and I've been quite happy with it. But I've found it's limited in resolution. By that I mean that wide whole of sheet photos can lack resolution with stars that are particularly small/fine.

Below is an example, the one on the right is an A4 sketch (NGC 4945), and on the left is an A1 piece (LMC).

238206 , 238207

When you then actually get in close to the actual piece to photograph it, you notice a BIG difference in what the whole of piece photo just doesn't pickup. For the photos below I got in closer to the pieces:

238208 , 238209

The SX60HS has 16mega pixels, but the chip size is 6.17mm X 4.55mm. I suspect that the sensor is just too small in size to pick up the detail, despite the number of pixels. I've seen a similar sort of lack of resolution when I've used my Brinno time lapse camera, which is why I suspect its the actual size of the chip of the SX60 that is the cause of my problem.

As part of the equation, I need to also mention that the camera is set approx 2m from the piece to reduce the amount of lens distortion one would get from having the camera set closer.

238210

So, I need help in finding a GOOD camera that can give me the necessary resolution and also produce a damn fine image.

I've been looking at a couple cameras, the Canon 6D and the 600D. I'm aware of the difference in chip size of both cameras, but I'm also aware of the cost difference between the two, and that too is a big factor. I've not settled solely on Canon cameras, and I am VERY much open to other brands. They just need to be able to produce the goods.

If I've missed out on any technical aspects, please let me know too.

Thanks for looking and your consideration.

Alex.

[Ausrock]

Alex,

I'd been looking to upgrade from a Canon 40D due to dissatisfaction with results after a trip to Broome a few months ago, I'd upgraded to L series lenses for the trip and was ultimately disappointed.

Research and talking to people who know their stuff ultimately led me to the 6d mkII which I bought a couple of days ago.......haven't had time to play with it yet but current sale prices can't be beaten.

:cool2:

[Merlin66]

Interesting...
My wife regularly copies genealogy documentation and photos and has settled on a Panasonic LUMIX TC90. It works very well for her.
What macro lens are you using?
Never tried it in earnest but my Canon 80mm prime lens is said to be capable.

[mental4astro]

Ken,

The SX60HS lens is not interchangeable:

https://en.wikipedia.org/wiki/Canon_PowerShot_SX60_HS

For macro, true macro, it does really well:

238213

The camera was just 30mm from the spider.

If I get in really close to my sketches, the camera does really well. You see that in the second batch of photos in the first post - I've edited the first post to be clear on that (thanks Ken). But if I come in too close to the sketch with the camera, in order to get the whole sketch in the frame, the lens introduces too much distortion.

[peterl]

Hi Alexander,
My understanding is you would like to copy your good sketches well enough to reproduce and print to keep or sell , or to keep best quality digital files backed up somewhere.
A camera regardless of how good it is will always bring in slight distortion either from not being square on to your work to be copied or from slight lens distortion which will change your image slightly from your original.
A good flatbed scanner these days will copy your images with hi resolution and no distortion. A camera will often copy well in close up and the further you move away from your work the harder it is to keep the sharp quality of your sketches. A lot of cameras today will copy this work for you but you will need a good copy stand, a remote release and good lighting from both sides approx 45 degrees angle.to reduce reflection.May slight enhancement in photoshop.
Even a reasonably good canon flatbed scanner will do the job for you very easily and fast.
You only need about 600 dpi on the scan and it will pick up the dust specks off your chalk or pencils.
Is that a help?

Peter langdown

[mental4astro]

Peter, you are right about what I want to be able to do with these pictures.

I've tried scanners. Problem is they introduce a lot of glare because the light does not come in at an angle - the very thing you suggested with a photographic stand. Most scanner won't be able to deal with an A2 or A1 size piece. For that matter, most scanners won't be able to deal with A3. Also, scanners also struggle with the nature of my work - subtle white details on black paper. They are not able to pick up the subtle nebulosity details - low contrast on a very dark background. This is why I've gone down the photographic route.

I have the lighting set up exactly as you suggested. I even do this with my sketching at the eyepiece for the very same reason - to reduce the amount of glare coming off the page. Funny enough when people come up to me while I'm sketching, they first stand directly opposite from where the light source is pointing, so they don't actually see anything and wonder how I'm actually doing this. That's until I make them stand where I do while I'm sketching - then everything makes sense... :lol: Anyways, when so many of the sketches involve gossamer-like soft nebulosity, like my recent piece of the Flame and Horse Head, a scanner just wouldn't be able to pull the nebulous detail:

238218

I wonder if it's not just a matter of looking to try a larger format chip in order to suss out their capability compared to my own SX60. As you mentioned, from up close my camera does very well. The problem comes when the camera is set further away. Reason why I'm asking about larger format cameras is because of their ability to pick up wee details, such as pinpoint faint stars while photographing the Milky Way.


Anyone have a camera I could try? I'd be happy to bring the piece to your place for this as you would be familiar with its settings, and is a precious bit of kit. I could bring two or three different sketches to try out different scenarios.

Alex.

[peterl]

Hi Alexander,
All the flatbed scanners that I use and know of have the scanning light at an angle.
I can scan glossy papers etc and not even a hint of reflection.
you images are mostly on black fairly flat surface so that is not a problem

with reflection.As far as subtle nebulae and faint sketching a good scanner will always pick this up every time just need the scanner settings set correctly which is easy to do. I restore old photographic images and some of them you can barely make out any detail with fading.
photoshop enhances these very well. With scanning any thing bigger than a4 or a2 I scan in 3 or 4 or more scans and stitch them together in photoshop and you have a perfect big image with no joins.I often have to scan large maps etc that are bigger than a3 or a2 with some scans up to 20 photoshop will stitch these well.
What model scanner do you use.Is it a flat bed type?
Peter

[Wavytone]

Hi Alex, I've tried this before with both large artwork and engineering drawings. FWIW I used to have an A3 Microtek scanner years ago, but eventually sold it when I no longer needed it.

For a modest outlay a large flatbed scanner is the way to go because ultimately the number of pixels it can produce will vastly exceed the pixels available from single frame of a camera sensor and the resolution available from camera lenses - even the best ones. Sure you could make a mosaic of several images stitched, but a flatbed can do that too.

For a small volume of scans there are also bureaus that can scan anything up to 56" wide as a continuous sheet for a modest cost. This I suggest will be far the best option rather than buying a large scanner. You may have to stay and be there to get it right, but once you know the settings its straightforward.

The camera idea has a whole host of issues starting with uneven lighting. It's hard enough using a camera to copy A4 - I've used my Panasonic GX85 and GX series lenses with fair results - but far from perfect and nowhere near as good as a flatbed can do.

[tlgerdes]

Plus the resolution is going to be massively increased with a scanner compared to camera.

I can do A3 on mine at up 1200dpi, that works out at over 500 Megapixels. Even at 600dpi for an A4 is over 33 Megapixels.

A3 on a 20Mp camera is going to lose more detail.

[silv]

scanner or ... you could stitch together a mosaic of 4 or 3x3 photos taken at a distance of 30cm like you did with that gorgeous spider.
There's mosaic software people are using for milky way mosaics. Lo and behold, Wiki has even a comparison table for that. https://en.wikipedia.org/wiki/Comparison_of_photo_stitching_softw are
I never stitched a mosaic but I assume it could solve your challenge of digitising your beautiful sketches. Prop them against a wall or on an easel, camera on a tripod real close and take the photos with overlapping areas at the "seams".

[mental4astro]

One other reason why I'm hesitant of using a scanner is it requires so much handling of these delicate pieces. Soft pastel is easily damaged, so to be dragging a sketch across a scanner to ultimately stitch together sections is not going to happen. Spraying a fixative on the sketches is also not an option as the varnish and calcium carbonate share a very similar refractive index, so as you spray, the sketch disappears! Not so simple, eh... There is also a huge risk with the larger pieces that with so much handling that the paper will be creased or damaged. I've handled enough paper to know no matter how careful you are, the more you handle it the greater the likelihood of damage.

I do understand what is being said about what scanners can offer, and I've been rethinking scanners as a result. I also understand the nature of my pieces and what I can and can't do with them. Like everyone, I'm not going to put my work at risk.

Annette, you've presented a good alternative - stitch photos together.

My care for my work extends to how I store them. Finished pieces are not left to languish in the sketch pads. I've even devised contraptions that help me control dew while I'm sketching, so now just the heaviest of dew stops me, as it would stop everyone's own efforts at what they do. So I am very familiar with handling my stuff. I say this so you have a little insight into not just the production but also the care that goes into these pieces. There's even a little materials science thrown in for good measure!

What will happen is more experimentation. I will look into scanners all the same, including large professional units to see what will cause the least compromise to my work. I'll also try different cameras and Photoshop - I never thought I'd be using astro-inspired mosaic software with my sketches!! :lol:

Alex.

[peterl]

Here is another option for you.
As I mentioned before I often scan maps, photos and have scanned old very fragile silk maps from world war 2 that some paratroopers had in their pockets to use at night so the silk would not make a noise near the enemy.
Some old maps I scan are so fragile we cannot handle or move around too much or the paper will flake apart. The old way was to hold the map above the scanner and scan in many pieces.This way will damage these maps etc.


You mentioned that your image being damaged by dragging the image across the scanner and destroying the detail. True! This was a problem I had with artwork I was given to scan like pastels etc.
The solution I now use is a canon LIDE 220 flatbed scanner scanning upside down with a handle mounted to the unit so your sketches can stay flat on a table.The scanner is lifted up and down gently without a single smudge.
The scanner will optically scan at 1200 dpi but 300 to 600 for you will be fine, depending on how large you want to reproduce these images. Here is a website you can look at if you want to go this way. It certainly solved these problems.
https://mpetroff.net/2013/09/scanner-modifications-to-scan-large-documents/
Not all scanners will be able to scan upside down . Also scanning with a flatbed scanner your images scanned will always be straight so saving and tidying up later is easy.


Just a suggestion Alex.


Peter

[peterl]

One thing I did not mention that with modding this scanner the raised plastic lip around the top edge of the scanner is removed so there is no shadow or bad edges on your scans if there are multiple scans for stitching later. :)


peter

[mental4astro]

Peter, this Canon scanner you've mentioned and how you use it is absolutely fascinating! This changes everything and gives me a practical alternative to photos. I've sent you a PM about sending you a test piece to try if you can.

Alex.